Researchers have lifted the veil of secrecy over the state of the human brain at the moment of dying man. The results cast doubt on the conclusions previously drawn from the autopsy and investigation of dead brain tissue.
Richard Myers of Stanford University and his colleagues found that a patient in a coma for a different set of active genes than in those who quickly dies of a heart attack.
Using a chip that carries thousands of genes, the researchers tested which of them are active in the brains of 40 deceased (among them were suffering from depression, manic-depressive psychosis, schizophrenia and healthy people). Scientists searched genes that are abnormally active, and accordingly, may cause mental disorders. Instead, they noticed that the samples could be divided into two groups — depending on how the person died. Those who are close to death a few hours or days, showed a genetic profile, and those who had died suddenly — the other.
With a long illness brain may experience a lack of oxygen and sugars, which may make it to activate a set of genes, designed to help cells survive. In addition, the dying brain inhibits the activity of genes associated with metabolism, possibly because the cells are deprived of essential nutrients. In patients who died immediately, brain tissue was more acidic. This may be due to the fact that the cells are deprived of oxygen for energy production release acidic byproducts, such as lactic acid. It is possible that brain death occurs after experiencing some acid threshold.
Battery News, 05/02/2004 10:25